/**
 * This jQuery plugin displays pagination links inside the selected elements.
 * 
 * This plugin needs at least jQuery 1.4.2
 *
 * @author Gabriel Birke (birke *at* d-scribe *dot* de)
 * @version 2.2
 * @param {int} maxentries Number of entries to paginate
 * @param {Object} opts Several options (see README for documentation)
 * @return {Object} jQuery Object
 */
define("lib/cmd-plugins/pagination/2.2.0/pagination", [ "lib/jquery/1.11.1/jquery" ], function(require) {
    var $ = require("lib/jquery/1.11.1/jquery");
    (function($) {
        /**
	 * @class Class for calculating pagination values
	 */
        $.PaginationCalculator = function(maxentries, opts) {
            this.maxentries = maxentries;
            this.opts = opts;
        };
        $.extend($.PaginationCalculator.prototype, {
            /**
		 * Calculate the maximum number of pages
		 * @method
		 * @returns {Number}
		 */
            numPages: function() {
                return Math.ceil(this.maxentries / this.opts.items_per_page);
            },
            /**
		 * Calculate start and end point of pagination links depending on 
		 * current_page and num_display_entries.
		 * @returns {Array}
		 */
            getInterval: function(current_page) {
                var ne_half = Math.floor(this.opts.num_display_entries / 2);
                var np = this.numPages();
                var upper_limit = np - this.opts.num_display_entries;
                var start = current_page > ne_half ? Math.max(Math.min(current_page - ne_half, upper_limit), 0) : 0;
                var end = current_page > ne_half ? Math.min(current_page + ne_half + this.opts.num_display_entries % 2, np) : Math.min(this.opts.num_display_entries, np);
                return {
                    start: start,
                    end: end
                };
            }
        });
        // Initialize jQuery object container for pagination renderers
        $.PaginationRenderers = {};
        /**
	 * @class Default renderer for rendering pagination links
	 */
        $.PaginationRenderers.defaultRenderer = function(maxentries, opts) {
            this.maxentries = maxentries;
            this.opts = opts;
            this.pc = new $.PaginationCalculator(maxentries, opts);
        };
        $.extend($.PaginationRenderers.defaultRenderer.prototype, {
            /**
		 * Helper function for generating a single link (or a span tag if it's the current page)
		 * @param {Number} page_id The page id for the new item
		 * @param {Number} current_page 
		 * @param {Object} appendopts Options for the new item: text and classes
		 * @returns {jQuery} jQuery object containing the link
		 */
            createLink: function(page_id, current_page, appendopts) {
                var lnk, np = this.pc.numPages();
                page_id = page_id < 0 ? 0 : page_id < np ? page_id : np - 1;
                // Normalize page id to sane value
                appendopts = $.extend({
                    text: page_id + 1,
                    classes: ""
                }, appendopts || {});
                if (page_id == current_page) {
                    lnk = $("<span class='current'>" + appendopts.text + "</span>");
                } else {
                    lnk = $("<a>" + appendopts.text + "</a>").attr("href", this.opts.link_to.replace(/__id__/, page_id));
                }
                if (appendopts.classes) {
                    lnk.addClass(appendopts.classes);
                }
                if (appendopts.rel) {
                    lnk.attr("rel", appendopts.rel);
                }
                lnk.data("page_id", page_id);
                return lnk;
            },
            // Generate a range of numeric links 
            appendRange: function(container, current_page, start, end, opts) {
                var i;
                for (i = start; i < end; i++) {
                    this.createLink(i, current_page, opts).appendTo(container);
                }
            },
            getLinks: function(current_page, eventHandler) {
                var begin, end, interval = this.pc.getInterval(current_page), np = this.pc.numPages(), fragment = $("<div class='pagination'></div>");
                // Generate "Previous"-Link
                if (this.opts.prev_text && (current_page > 0 || this.opts.prev_show_always)) {
                    fragment.append(this.createLink(current_page - 1, current_page, {
                        text: this.opts.prev_text,
                        classes: "prev",
                        rel: "prev"
                    }));
                }
                // Generate starting points
                if (interval.start > 0 && this.opts.num_edge_entries > 0) {
                    end = Math.min(this.opts.num_edge_entries, interval.start);
                    this.appendRange(fragment, current_page, 0, end, {
                        classes: "sp"
                    });
                    if (this.opts.num_edge_entries < interval.start && this.opts.ellipse_text) {
                        $("<span>" + this.opts.ellipse_text + "</span>").appendTo(fragment);
                    }
                }
                // Generate interval links
                this.appendRange(fragment, current_page, interval.start, interval.end);
                // Generate ending points
                if (interval.end < np && this.opts.num_edge_entries > 0) {
                    if (np - this.opts.num_edge_entries > interval.end && this.opts.ellipse_text) {
                        $("<span>" + this.opts.ellipse_text + "</span>").appendTo(fragment);
                    }
                    begin = Math.max(np - this.opts.num_edge_entries, interval.end);
                    this.appendRange(fragment, current_page, begin, np, {
                        classes: "ep"
                    });
                }
                // Generate "Next"-Link
                if (this.opts.next_text && (current_page < np - 1 || this.opts.next_show_always)) {
                    fragment.append(this.createLink(current_page + 1, current_page, {
                        text: this.opts.next_text,
                        classes: "next",
                        rel: "next"
                    }));
                }
                $("a", fragment).click(eventHandler);
                return fragment;
            }
        });
        // Extend jQuery
        $.fn.pagination = function(maxentries, opts) {
            // Initialize options with default values
            opts = $.extend({
                items_per_page: 10,
                num_display_entries: 11,
                current_page: 0,
                num_edge_entries: 0,
                link_to: "#",
                prev_text: "Prev",
                next_text: "Next",
                ellipse_text: "...",
                prev_show_always: true,
                next_show_always: true,
                renderer: "defaultRenderer",
                show_if_single_page: false,
                load_first_page: true,
                callback: function() {
                    return false;
                }
            }, opts || {});
            var containers = this, renderer, links, current_page;
            /**
		 * This is the event handling function for the pagination links. 
		 * @param {int} page_id The new page number
		 */
            function paginationClickHandler(evt) {
                var links, new_current_page = $(evt.target).data("page_id"), continuePropagation = selectPage(new_current_page);
                if (!continuePropagation) {
                    evt.stopPropagation();
                }
                evt.preventDefault();
                return continuePropagation;
            }
            /**
		 * This is a utility function for the internal event handlers. 
		 * It sets the new current page on the pagination container objects, 
		 * generates a new HTMl fragment for the pagination links and calls
		 * the callback function.
		 */
            function selectPage(new_current_page) {
                // update the link display of a all containers
                containers.data("current_page", new_current_page);
                links = renderer.getLinks(new_current_page, paginationClickHandler);
                containers.empty();
                links.appendTo(containers);
                // call the callback and propagate the event if it does not return false
                var continuePropagation = opts.callback(new_current_page, containers);
                return continuePropagation;
            }
            // -----------------------------------
            // Initialize containers
            // -----------------------------------
            current_page = parseInt(opts.current_page, 10);
            containers.data("current_page", current_page);
            // Create a sane value for maxentries and items_per_page
            maxentries = !maxentries || maxentries < 0 ? 1 : maxentries;
            opts.items_per_page = !opts.items_per_page || opts.items_per_page < 0 ? 1 : opts.items_per_page;
            if (!$.PaginationRenderers[opts.renderer]) {
                throw new ReferenceError("Pagination renderer '" + opts.renderer + "' was not found in jQuery.PaginationRenderers object.");
            }
            renderer = new $.PaginationRenderers[opts.renderer](maxentries, opts);
            // Attach control events to the DOM elements
            var pc = new $.PaginationCalculator(maxentries, opts);
            var np = pc.numPages();
            containers.off("setPage").on("setPage", {
                numPages: np
            }, function(evt, page_id) {
                if (page_id >= 0 && page_id < evt.data.numPages) {
                    selectPage(page_id);
                    return false;
                }
            });
            containers.off("prevPage").on("prevPage", function(evt) {
                var current_page = $(this).data("current_page");
                if (current_page > 0) {
                    selectPage(current_page - 1);
                }
                return false;
            });
            containers.off("nextPage").on("nextPage", {
                numPages: np
            }, function(evt) {
                var current_page = $(this).data("current_page");
                if (current_page < evt.data.numPages - 1) {
                    selectPage(current_page + 1);
                }
                return false;
            });
            containers.off("currentPage").on("currentPage", function() {
                var current_page = $(this).data("current_page");
                selectPage(current_page);
                return false;
            });
            // When all initialisation is done, draw the links
            links = renderer.getLinks(current_page, paginationClickHandler);
            containers.empty();
            if (np > 1 || opts.show_if_single_page) {
                links.appendTo(containers);
            }
            // call callback function
            if (opts.load_first_page) {
                opts.callback(current_page, containers);
            }
        };
    })(jQuery);
});